bitops.h 4.9 KB

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  1. #ifndef _LINUX_BITOPS_H
  2. #define _LINUX_BITOPS_H
  3. #include <asm/types.h>
  4. #ifdef __KERNEL__
  5. #define BIT(nr) (1UL << (nr))
  6. #define BIT_ULL(nr) (1ULL << (nr))
  7. #define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
  8. #define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
  9. #define BIT_ULL_MASK(nr) (1ULL << ((nr) % BITS_PER_LONG_LONG))
  10. #define BIT_ULL_WORD(nr) ((nr) / BITS_PER_LONG_LONG)
  11. #define BITS_PER_BYTE 8
  12. #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
  13. #endif
  14. extern unsigned int __sw_hweight8(unsigned int w);
  15. extern unsigned int __sw_hweight16(unsigned int w);
  16. extern unsigned int __sw_hweight32(unsigned int w);
  17. extern unsigned long __sw_hweight64(__u64 w);
  18. /*
  19. * Include this here because some architectures need generic_ffs/fls in
  20. * scope
  21. */
  22. #include <asm/bitops.h>
  23. #define for_each_set_bit(bit, addr, size) \
  24. for ((bit) = find_first_bit((addr), (size)); \
  25. (bit) < (size); \
  26. (bit) = find_next_bit((addr), (size), (bit) + 1))
  27. /* same as for_each_set_bit() but use bit as value to start with */
  28. #define for_each_set_bit_from(bit, addr, size) \
  29. for ((bit) = find_next_bit((addr), (size), (bit)); \
  30. (bit) < (size); \
  31. (bit) = find_next_bit((addr), (size), (bit) + 1))
  32. #define for_each_clear_bit(bit, addr, size) \
  33. for ((bit) = find_first_zero_bit((addr), (size)); \
  34. (bit) < (size); \
  35. (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
  36. /* same as for_each_clear_bit() but use bit as value to start with */
  37. #define for_each_clear_bit_from(bit, addr, size) \
  38. for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
  39. (bit) < (size); \
  40. (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
  41. static __inline__ int get_bitmask_order(unsigned int count)
  42. {
  43. int order;
  44. order = fls(count);
  45. return order; /* We could be slightly more clever with -1 here... */
  46. }
  47. static __inline__ int get_count_order(unsigned int count)
  48. {
  49. int order;
  50. order = fls(count) - 1;
  51. if (count & (count - 1))
  52. order++;
  53. return order;
  54. }
  55. static inline unsigned long hweight_long(unsigned long w)
  56. {
  57. return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
  58. }
  59. /**
  60. * rol64 - rotate a 64-bit value left
  61. * @word: value to rotate
  62. * @shift: bits to roll
  63. */
  64. static inline __u64 rol64(__u64 word, unsigned int shift)
  65. {
  66. return (word << shift) | (word >> (64 - shift));
  67. }
  68. /**
  69. * ror64 - rotate a 64-bit value right
  70. * @word: value to rotate
  71. * @shift: bits to roll
  72. */
  73. static inline __u64 ror64(__u64 word, unsigned int shift)
  74. {
  75. return (word >> shift) | (word << (64 - shift));
  76. }
  77. /**
  78. * rol32 - rotate a 32-bit value left
  79. * @word: value to rotate
  80. * @shift: bits to roll
  81. */
  82. static inline __u32 rol32(__u32 word, unsigned int shift)
  83. {
  84. return (word << shift) | (word >> (32 - shift));
  85. }
  86. /**
  87. * ror32 - rotate a 32-bit value right
  88. * @word: value to rotate
  89. * @shift: bits to roll
  90. */
  91. static inline __u32 ror32(__u32 word, unsigned int shift)
  92. {
  93. return (word >> shift) | (word << (32 - shift));
  94. }
  95. /**
  96. * rol16 - rotate a 16-bit value left
  97. * @word: value to rotate
  98. * @shift: bits to roll
  99. */
  100. static inline __u16 rol16(__u16 word, unsigned int shift)
  101. {
  102. return (word << shift) | (word >> (16 - shift));
  103. }
  104. /**
  105. * ror16 - rotate a 16-bit value right
  106. * @word: value to rotate
  107. * @shift: bits to roll
  108. */
  109. static inline __u16 ror16(__u16 word, unsigned int shift)
  110. {
  111. return (word >> shift) | (word << (16 - shift));
  112. }
  113. /**
  114. * rol8 - rotate an 8-bit value left
  115. * @word: value to rotate
  116. * @shift: bits to roll
  117. */
  118. static inline __u8 rol8(__u8 word, unsigned int shift)
  119. {
  120. return (word << shift) | (word >> (8 - shift));
  121. }
  122. /**
  123. * ror8 - rotate an 8-bit value right
  124. * @word: value to rotate
  125. * @shift: bits to roll
  126. */
  127. static inline __u8 ror8(__u8 word, unsigned int shift)
  128. {
  129. return (word >> shift) | (word << (8 - shift));
  130. }
  131. /**
  132. * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
  133. * @value: value to sign extend
  134. * @index: 0 based bit index (0<=index<32) to sign bit
  135. */
  136. static inline __s32 sign_extend32(__u32 value, int index)
  137. {
  138. __u8 shift = 31 - index;
  139. return (__s32)(value << shift) >> shift;
  140. }
  141. static inline unsigned fls_long(unsigned long l)
  142. {
  143. if (sizeof(l) == 4)
  144. return fls(l);
  145. return fls64(l);
  146. }
  147. /**
  148. * __ffs64 - find first set bit in a 64 bit word
  149. * @word: The 64 bit word
  150. *
  151. * On 64 bit arches this is a synomyn for __ffs
  152. * The result is not defined if no bits are set, so check that @word
  153. * is non-zero before calling this.
  154. */
  155. static inline unsigned long __ffs64(u64 word)
  156. {
  157. #if BITS_PER_LONG == 32
  158. if (((u32)word) == 0UL)
  159. return __ffs((u32)(word >> 32)) + 32;
  160. #elif BITS_PER_LONG != 64
  161. #error BITS_PER_LONG not 32 or 64
  162. #endif
  163. return __ffs((unsigned long)word);
  164. }
  165. #ifdef __KERNEL__
  166. #ifndef find_last_bit
  167. /**
  168. * find_last_bit - find the last set bit in a memory region
  169. * @addr: The address to start the search at
  170. * @size: The maximum size to search
  171. *
  172. * Returns the bit number of the first set bit, or size.
  173. */
  174. extern unsigned long find_last_bit(const unsigned long *addr,
  175. unsigned long size);
  176. #endif
  177. #endif /* __KERNEL__ */
  178. #endif